Halbach array electromagnet with substantially contiguous vertical and horizontal cores

ABSTRACT

Electromagnetic Halbach array device with substantially contiguous vertical and horizontal cores, comprised of a plurality of horizontal and vertical electromagnets arranged in a Halbach array sequence, where each individual core of every horizontal electromagnet in said Halbach array is equipped with a plurality of fork-like prongs at each end, and where the magnetic coils that surround each individual core of every vertical electromagnet in said Halbach array have gaps where said fork-like prongs are positioned to provide direct physical contact between cores.

FEDERALLY SPONSORED RESEARCH

Not applicable

SEQUENCE LISTING OR PROGRAM

Not applicable

BACKGROUND

1. Field of Invention

This invention relates to a novel Halbach array electromagnet withsubstantially contiguous vertical and horizontal cores. In verysimplified terms, a Halbach array effect can be visualized as elasticlooping streams of magnetic force emanating like fountains from thepoles of the magnets in the array, where sets of three adjacent, similarpoles magnify the fountains of magnetic force on one side of the arraywhile elastically decreasing or cancelling the fountains on the oppositeside of the array, which only have alternating north and south poles.

Permanent magnets are singular, inherently magnetized polar structures,as such they are relatively easy to orient and assemble in theprescribed sequence to enable the Halbach array effect. Electromagnetshowever, are structurally and functionally different from permanentmagnets since they are comprised of two elements, an energized magneticcoil and an artificially magnetized core segment or tooth (hereinafterreferred to as vertical or horizontal core or cores for simplicity).

Merely orienting and assembling electromagnets in a Halbach arraysequence does not generally enable a useful Halbach array effect, sincethe magnetic coils surrounding the vertical core acts as a physical andenergized barrier that prevents direct contact with the horizontal core.

Without substantial contiguity between cores, the Halbach array effectcan be diminished or even negated, resulting in an ordinary, unenhancedelectromagnet.

2. Description of Prior Art

In prior art most closely resembling but fundamentally different fromthe present invention, the electromagnets used are merely oriented andarranged as Halbach arrays, but there is no provision for establishingdirect physical connectivity between the vertical and horizontal cores.The magnetic coils act as a barrier that isolates the two cores, whichseverely decreases or even negates the Halbach array effect to the pointthat it generally results in an ordinary unenhanced electromagnet. Thisis similar to U.S. Pat. No. 7,598,646 which presents electromagnetsmerely arranged in Halbach array sequence but whose vertical andhorizontal cores are clearly isolated by the magnetic coils in thedrawings and the description. As such it does not offer substantialcontiguity between cores to ensure the direct transfer of flux necessaryto guarantee the proper generation of the Halbach array effect, in sharpcontrast to the present invention. As such it is fundamentally differentand likely far less effective, less efficient and less controllable thanthe present invention. Likewise, U.S. Pat. No. 7,541,813 is anapplication for oil drilling, where the cylindrical electromagnets useddo not provide contiguous cores, as indicated by the drawings provided.This is also the case of U.S. Pat. No. 5,705,902 which uses Halbacharrays within a generator but there is clearly no contiguity between itsoctagonal cores.

Most prior art that supposedly offer Halbach array electric motors onlyhave permanent magnets arranged as Halbach arrays, however theelectromagnets used are ordinary, standard, non-Halbach configurations.This is the case of U.S. Pat. No. 7,352,096 where two permanent magnetHalbach arrays on two backing plates sandwich a three phase non-Halbacharray stator that uses Litz wire winding, and is thus fundamentallydifferent from the present invention. This is also the case for U.S.Pat. No. 8,183,731 discloses a generator that uses permanent magnetsmounted on discs and spaced so far apart that it is unlikely to have astrong Halbach array effect. The single reversing electromagnet detaildrawing provided clearly does not pertain to a Halbach array and is thusdifferent from the present invention. Likewise, U.S. Pat. Nos.7,540,004, 7,031,116, 6,906,446, 6,841,910 and 6,858,962 disclosespermanent magnet Halbach arrays on the rotor, but the electromagneticstator is also non-Halbach, or not an electromagnet, and requiring aseparate non-Halbach commercially available drive motor. As such, theyare all fundamentally different from the present invention.

U.S. Pat. No. 8,264,314 discloses how to arrange a set of permanentmagnets to increase magnetic flux. The same is true with U.S. Pat. No.8,009,001 which discloses ‘hyper’ Halbach permanent magnet arrays. Bothdo not disclose Halbach array electromagnets and is thus a differentcategory from the present invention.

OBJECTS AND ADVANTAGES

Several objects and advantages of the present invention are:

-   -   a) to provide a Halbach array electromagnet with substantially        contiguous vertical and horizontal cores that closely replicates        permanent magnet Halbach arrays to maximize its effectiveness;    -   b.) to harness the magnified and directed nature of Halbach        array forces to increase the efficiency of electric motors that        utilizes Halbach array electromagnets as one of its components,        potentially enabling more powerful motors of the same size or        smaller motors with the same power;    -   c.) to reduce the weight of an electric motor that utilizes        Halbach array electromagnets by harnessing the magnified        magnetic forces inherent in Halbach arrays, and by removing the        need for metal back plates that would normally be required to        complete the non-Halbach electromagnet's circuit;    -   d.) to enable the opportunity to switch or use both sides of a        Halbach array electromagnet for various applications such as        pumps, actuators, transmissions, rechargers, etc; and    -   e.) to provide more efficient and controllable Halbach array        electromagnets equipped with substantially contiguous cores, to        replace permanent magnets in various applications or devices.

Further objects and advantages shall become apparent after consideringthe ensuing descriptions and drawings.

SUMMARY

The present invention solves a long existing and yet long unresolvedneed for substantial contiguity between the horizontal and verticalcores of a Halbach array electromagnet to maximize the efficiency ofelectric motors and other electromagnetic applications that aim toharness the magnified and directed magnetic forces generated by theHalbach array effect. Newer electric motors and other devices designedto integrate the present invention can either generate more power forthe same amount of energy consumed, or provide the same amount of powerwhile consuming significantly less energy. The present invention alsoenables a finer degree of control than prior art.

DRAWINGS Drawing Figures

In the drawings, closely related figures have the same number butdifferent alphabetic suffixes.

FIG. 1A is a close up view of an axial Halbach array electromagnet withsubstantially contiguous cores. It highlights how the fork-like prongsof the horizontal electromagnet's core slips through gaps in thevertical electromagnet's magnetic coils to achieve direct and maximalflux transfer between vertical and horizontal cores to generate astrongest possible Halbach array effect.

FIG. 1B shows an overview of the sequence and orientation of verticaland horizontal electromagnets in an inner axial Halbach array used as astator mounted on a central hub. It also shows the origin of the closeup view in FIG. 1A. Note that the outer ring is likewise a Halbacharray, but it is comprised of permanent magnets that are embedded intothe alloy wheel of a car (not shown) to serve as a rotor. The permanentmagnets and the central hub are not part of the present invention. It isonly included to illustrate one possible application for the presentinvention, in this case as a component of an electric motor.

FIG. 2 shows a sample wiring layout for an inner axial Halbach arrayelectromagnet in FIG. 1B, which will be used for both vertical andhorizontal electromagnetic cores.

FIG. 3A shows permanent magnets arranged as Halbach arrays, with anapproximation of the contrasting height of magnetic flux it produces.The drawing highlights the ‘flux aperture’ of each set of three adjacentsimilar magnetic poles which combine to magnify flux on one side whileelastically decreasing or cancelling the magnetic flux on the other sideof the Halbach array, which only has alternating north and south poles.This figure does not include any part of the present invention and isthus provided only for completeness. Straight lines were chosen toidentify the flux aperture for clarity. This drawing is directlycomparable to the next two figures, to emphasize significant differencesbetween permanent magnets, prior art non-contiguous electromagnetsmerely arranged in Halbach sequence, and true contiguous core Halbacharray electromagnets of the present invention.

FIG. 3B is oriented for direct comparison with FIG. 3A, but now showinga cut-away view of electromagnets that are merely arranged in a Halbacharray sequence, with magnetic coils acting as a physical and activebarrier preventing contiguity between cores. It also shows that there isno ‘flux aperture’ whatsoever to connect the sets of similar poles (in amanner similar to FIG. 3A), significantly diminishing the transfer offlux needed to generate the Halbach array effect. This figure is doesnot embody the present invention and is only provided for completeness,to discuss the shortcomings of prior art.

FIG. 4 shows a cut-away, close-up view of a linear, dual-sided Halbacharray electromagnet, as another embodiment of the present invention,still oriented for direct comparison with FIG. 3A and FIG. 3B. It showshow the fork-like prongs re-establish the required ‘flux aperture’,penetrating the vertical core's magnetic coils to achieve substantialcontiguity between cores, maximizing flux transfer to generate thestrongest possible Halbach array effect in electromagnets. The octagonalshapes represent just one example for the location of attachment points,but for the sake of clarity, other attachment locations or attachmentstructures were not shown.

FIG. 5 shows how an inner axial Halbach array electromagnet withcontiguous cores (originally shown in FIG. 1B) is used as a statormounted to a central hub, for use in an electric motor. The outerHalbach array is the rotor that utilizes permanent magnets, which areaffixed on the inner rim of a car's alloy wheel (not shown). The twosets of integrated three-phase wires that result from winding in FIG. 2(detail not shown, but seen clearly in FIG. 1A) is connected to athree-phase DC controller (shown), which is then connected to othersimilarly off-the-shelf components for powering an electric vehicle.This simplified, sample diagram contains various items which are notpart of the present invention and is thus only provided forcompleteness.

REFERENCE NUMERALS IN DRAWINGS

-   101 Vertical electromagnets of a Halbach array-   102 Horizontal electromagnets of a Halbach array-   103 Vertical electromagnet core or tooth-   104 Horizontal electromagnet core or tooth-   105 Magnetic coil surrounding vertical electromagnets-   106 Magnetic coil surrounding horizontal electromagnets-   107 Fork like prongs at the ends of each core or tooth of every    horizontal electromagnet-   108 Three-phase wires from magnetic coils for connection to the    controller-   109 Flux aperture between similar adjacent magnetic poles in a    Halbach array

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment of the present invention is achieved byintegrating a set of horizontal electromagnets 102 between a set ofvertical electromagnets 101, and arranging both in the prescribedHalbach array sequence, an example of which is shown in FIG. 1B, butensuring that the individual cores of both horizontal 104 and verticalelectromagnets 103 must be substantially contiguous as described in thenext paragraph. This novel Halbach array electromagnet withsubstantially contiguous vertical and horizontal cores can beimplemented as axial, linear, or other configurations for a multitude ofapplications, such as stators or rotors for electric motors.

The Halbach array sequence and orientation causes the magnetic coilssurrounding the vertical electromagnets 105 to ordinarily becomephysical and active barriers that separate the individual cores or teethof the horizontal 104 and vertical electromagnets 103. The presentinvention overcomes this barrier by introducing fork like prongs at theends of each core or tooth of every horizontal electromagnet 107 throughgaps made during the winding of aforementioned magnetic coil. Examplesof contiguous core Halbach array electromagnets are in FIG. 1A (axialconfiguration) and FIG. 4 (linear dual-sided configuration).

Because the process of winding may damage the film of insulationcovering the magnetic coil surrounding the vertical electromagnets 105,the use of optional insulating slot paper (not shown) such as that madefrom Nomex ™ and Mylar ™ is recommended. Since the magnetic coilsurrounding the horizontal electromagnet 106 generally does notinterfere with assembly, it can be wound prior to, or after insertion.

Alternative Embodiments

One alternative embodiment of form rather than function is driven byconvenience in manufacturing and assembly. It primarily uses modularstator or rotor core segments to facilitate automated winding, which arepre-configured to embed insulation and gaps in the magnetic coils. Thiswill be mated to a similarly modularized pre-wound horizontal core thatis equipped with fork like prongs at each end to provide substantialcontiguity between vertical and horizontal cores. This strategy willlikely yield the quickest assembly times compared to other options.

With 3D metal deposition printing, it is possible to create a mesh ofembedded electromagnets whereby each element of the core and coil can bemultiplied, miniaturized and meshed into Halbach arrays with contiguouscores. One exciting aspect would be spherical, helical or octagonalHalbach arrays with contiguous cores for experiments in energy and otherapplications, which was heretofore impossible before the advent of 3Dprinting. Possible variations of the present invention have thusbroadened considerably.

Operation—Preferred Embodiment

Since there are a multitude of applications that can benefit fromHalbach array electromagnets that offer substantially contiguous cores,it would be impossible to cover all of the possible permutations withregard to wiring and control, thus there is a need to provide a specificexample for the operation of the preferred embodiment. For the sake ofcompleteness, FIG. 2 provides a wiring pattern that can be usedspecifically with FIG. 1B to create an electric motor that uses thepresent invention as the inner stator mounted on a central hub, with anouter set of permanent magnets likewise arranged as a Halbach array,that can be affixed to an automobile's alloy wheel (not shown) as arotor.

In the wiring example in FIG. 2, there are three separate wiring phases,A, B, and C and is the same pattern is used for both horizontal andvertical electromagnets as separate sets. Winding is clockwise if theletter is capitalized, and counter clockwise if the letter is in lowercase in the diagram. Once this sample electric motor with its alloyrotor wheel is completed, tested and properly mounted, the two pairs ofvertical and horizontal stator cores can be physically hardwired andsimultaneously commutated by connecting each of the three-phase wires tothe appropriate contact points on commercially available singlethree-phase electric motor controller as shown in FIG. 5. Alternatively,the vertical and horizontal cores can be wired separately but still beelectronically interlocked and commutated simultaneously by connectingeach phase wire of each core to the appropriate contact points on a dualthree-phase electric motor controller, which would be perfect for thedual-sided configuration in FIG. 4. These electric motor controllers canbe procured from Kelly Controls ™, Roboteq ™, Azure Dynamics ™, TexasInstruments ™ and other manufacturers.

Once the present invention is connected as shown in the simplifieddiagram in FIG. 5, force applied to the pedals (not shown) attached tothe throttle and regenerative braking potentiometer boxes (labeled as‘pot’ box in the drawing) would be analogous to stepping on the gaspedal and brake pedal respectively, in a conventional car since thisultimately commands the three-phase electric motor controller to powerand commutate the inner stator (that embodies the present invention inthis particular example) to drive the rotor's permanent magnets (theouter Halbach array ring).

The diagram in FIG. 5 also shows the converted ‘ignition’ key switch,the subsystems for monitoring, charging and converting power from thebatteries, as well as the twelve volt circuitry and controller needed topower auxiliary system in the vehicle such as signal lights, wipers,etc. Most importantly the diagram also shows how contactors, fuses,diodes, current sensors and emergency shutoff switch are applied toensure safe operation. Again, this simplified diagram contains variousitems which are not part of the present invention and is thus onlyprovided as an example for completeness.

CONCLUSION, RAMIFICATIONS AND SCOPE

Generally the primary goal of any Halbach array implementation is tomaximize efficiency by harnessing the magnified and directedelectromagnetic forces produced; otherwise an ordinary, unenhancedelectromagnet would be used instead. The stack of coated thin sheets ofhigh-silicon electrical steel that comprise the vertical and horizontalcores have a magnetic resistance that is a thousand times less thanempty air. This means that core to core contiguity (measured by the fluxaperture 109 shown in FIG. 3A and FIG. 4) maximizes the flow of magneticflux, whereas relying upon empty air to transmit the magnetic fluxbetween isolated polar cores is massively inefficient (thus counter tothe original goal), substantially diminishing or even negating theHalbach array effect.

Moreover, magnetic coils are made of copper, different in compositionand intended function to the laminations of high-silicon electricalsteel which comprises the core. Thus when the magnetic coils surroundingthe vertical core obstructs the path of the magnetic flux produced bythe horizontal core (as shown in FIG. 3B) it has no flux aperture 109needed to enable a strong Halbach array effect. The magnetic flux willfollow a path of lesser magnetic resistance, however the magnetic coilsare energized wires and its energy is traveling at right angles of thehorizontal core's magnetic flux path. Since energized copper is not thesame as non-energized, absorbent high-silicon electrical steel of thecore, significant dispersion and misdirection of magnetic flux results,which is again massively inefficient, substantially diminishing or evennegating the Halbach array effect.

Thus the reader will see that the Halbach array electromagnet withsubstantially contiguous cores of the present invention provides afundamental solution a long existing and yet long unresolved need. It islikely the simplest and closest functional equivalent of permanentmagnet Halbach arrays as applied to electromagnets.

While the above description contains many specificities, these shouldnot be construed as limitations on the scope of the invention, butrather as an exemplification of one preferred embodiment thereof.

Accordingly, the scope of the invention should be determined not by theembodiments illustrated, but by the appended claims and their legalequivalents.

I claim:
 1. Electromagnetic Halbach array device with substantiallycontiguous vertical and horizontal cores, comprising: a) a pluralityhorizontal and vertical electromagnets arranged in a Halbach arraysequence, b) a plurality of fork-like prongs at the ends of eachindividual core of every horizontal electromagnet in said Halbach array,and c) gaps in the magnetic coils that surround each individual core ofevery vertical electromagnet in said Halbach array, where said fork-likeprongs are positioned to provide direct physical contact between cores.2. Halbach array electromagnetic device with conduits for directlytransmitting flux between vertical and horizontal cores, comprising: a)a plurality horizontal and vertical electromagnets arranged in a Halbacharray sequence, b) a plurality of fork-like prongs at the ends of eachindividual core of every horizontal electromagnet in said Halbach array,and c) gaps in the magnetic coils that surround each individual core ofevery vertical electromagnet in said Halbach array, where said fork-likeprongs are positioned to provide direct physical contact between cores.3. Method for creating an electromagnetic Halbach array device withsubstantially contiguous vertical and horizontal cores, comprising: a)arranging a plurality horizontal and vertical electromagnets in aHalbach array sequence, b) providing the ends of each individual core ofevery horizontal electromagnet in said Halbach array with a plurality offork-like prongs, and c) creating gaps in the magnetic coils thatsurround each individual core of every vertical electromagnet in saidHalbach array, so that said fork-like prongs can be inserted to providephysical contact between cores.